1. Field of Invention
The present invention relates to a sports boot, in particular a sports boot designed for skiing, mountaineering, and walking.
2. Background Information
To ensure user safety and provide optimum comfort during skiing, ski boots generally have a rigid shell within which a soft inner liner is inserted. The shell generally comprises a plurality of elements made of a relatively rigid composite plastic material, and the liner is constructed by assembling a plurality of foam or fabric panels.
The document EP-A-0 406 212 discloses an alpine ski boot comprising a lower portion provided to envelop the foot of the user, and an upper portion, or collar, provided to surround the lower leg. The collar is rotationally articulated with the lower portion about an axis corresponding to the articulation axis of the ankle of the user. The rearward rotation of the collar is locked so as to enable the rearward support of the legs of the skier during skiing. The boot allows for a slight forward rotation of the collar in order to enable the user to lean forward.
In alpine skiing, the user must sometimes walk a short distance to reach the top of a ski slope, when the ascent is carried out by cable car, for example. The substantial rigidity of the boot according to the document EP-A-0 0 406 212 makes it difficult to walk because the movements of the ankle are blocked by the boot.
Touring skis are equipped with bindings allowing the boot to pivot around its front end, so as to enable the heel to be lifted away from the ski. This movement involves longitudinal flexion and extension of the ankle, which is not allowed by alpine ski boots.
Touring ski boots are equipped with a mechanism for unlocking the rearward rotation of the collar, in order to facilitate the approach by allowing longitudinal flexion and extension of the ankle. However, the collar is not free to pivot laterally, which blocks the lateral flexional movements of the ankle, called inversion and eversion. Thus, touring ski boots are not adapted for the approach, in which the skier takes off his or her skis and moves on rough terrain, or for mountain climbing. Furthermore, touring ski boots are not any more adapted for the ascent phases on sloping zones which require a lateral inclination of the boot.
In this regard, the document EP-A-0 406 212 describes a mechanism for adjusting the lateral inclination, or “canting”, of the collar in relation to the lower portion of the boot, depending on the morphology of the legs of the skier. This adjustment is done prior to skiing and is not modified during use of the boot. The canting adjustment is not easy to achieve and often requires a tool.
In EP-A-0 406 212, a free position is provided, in which the collar can freely tilt laterally. However, the angular amplitude of this movement is limited to a few degrees, and friction makes lateral inclination difficult. Thus, the boot according to the document EP-A-0 406 212 is not adapted to allow an easy lateral flexional movement of the ankle during skiing or during walking.
Further, EP-A-1 880 623 discloses a ski boot having an increased lateral flexion amplitude. In the area of the ankle articulation, the boot comprises two ball-type connections. Two independent blocking mechanisms block the longitudinal flexion and extension of the ankle, on the one hand, and block the lateral flexion, on the other hand. This device is relatively heavy and complex and requires a bulky and projecting coupling plate. In addition, the collar of the boot cannot simultaneously tilt longitudinally and laterally, which limits the movements of the ankle.